Dry cleaning composition



Fatente'd Jul 28, 1942 l TED STATES PATENT --?OFFICE A 2.290.870 nay onmnmc COMPOSITION Eawrence H. Flatt, Hamburg, Y., assignor to Allied Chemical a Dye Corporation, a corporation of New York No Brawing.

Application January '14, 1939, Serial No. 250,918

Claims. -(Cl. 252 161)" This invention relates to improvements in the dry cleaning of fibrous, textile and related materials, It relates particularly to improved compositions for use in dry cleaning and to processes of dry cleaning in which said improved compositions are employed.

. It is well known that certain typ'esof ,tentile" fabrics and materials such as leather cannot be cleaned by means of ordinary soap and water since they are prone to shrink, harden, wrinkle and/or fade when they are wetted with water. For the cleaning;- of such materials a dry cleaning process must be used. In such dry cleaning processes, volatile organic solvents such as naphtha, trichlorethylene, carbon tetrachloride, gasoline, benzene, Stoddards solvent, etc. are used. These solvents are effective for removing from the fabrics or materials practically all greasestains as well as dust and dirt which commonly, adhere to the greasy spots. 'It is further known that if a small amount of water. is sumciently well dispersed inthe dry cleaning fluid that water-soluble stains such as those caused byjsugary liquidscandy, soft drinks, etc. are removed without adversely aifecting the material so treated.-

According to the present invention, a dry cleaning composition is used which contains as essential components a dry cleaning solvent or mixture of dry cleaning solvents and at least onesalt of a sulfonated fatty diester of a glycol. As

employed herein, the term sulfonated denotes generically sulfonate (sulfonic acid) and sulfate derivatives of the esters. Initspreferredform, the dry cleaning composition of this invention contains in addition a small amount of water.

The said sulfonated esters are the reaction products obtained by sulfating and/or sulfonating fatty acid'diesters of glycols, which esters contain at least one fatty acid residue capable of reacting with a sulfonating agent, and especially RCOO-G-OOCR' in which G represents the residue of a glycol and" R and R each respectively represents the'residue of a fatty acid, one or both of the residues R and R containing at least one double 'bond and/or at least one hydroxyl group. They are fatty acid diesters of glycols in which at least one of the fatty acid residues contains at least one sulfate or sulfonate group. I

Compounds of the above-described general class have been found to give excellent results in sulfation and/or sulfonation products of esters of glycols having the general formula:

. solution than was'heretofore' possible. With the improving dry cleaning compositions when added to such compositions, particularly if the said compositions also contain small amounts of water. However, it has been found that certain of these compounds giveeven better results than the class as a whole. Thus the salts of the abovedescribed sulfuric acid derivatives which contain an alkyl group of eight or more carbon atoms, particularly between twelve and eighteen carbon atoms, have been found to be moreefiective than those with an alkyl group of lower carbon content.

This invention contemplates the use of the suli'onated esters of the above general class in the form, of salts in which the acidic hydrogen of the sulfate and/or sulfonategroup is replaced by an inorganic or organic salt-forming radical. Among the more easily obtained salts are the ammonium, alkalimetal, and alkaline earth metal salts. Salts in which the acidic groups are neutralized by organic bases (such as mono-, di-, or tri-ethanolamine, pyridine, ethyleneamine,

I amylamine, triethylene-tetramine, etc.) also may be used. If the salt-forming basic radical 'is' fluid has been found to be particularly effective in enabling'the dry cleaning fluid, in which water is normally practically immiscible to hold in finely dispersed form a limited amount of water.

It has been found that by using the sulfonated esters of the class defined above a substantially greater amount of water in relation to the amount of dry cleaning assistant'present can be held in a well dispersed form in the dry cleaning dry cleaning assistants of this invention the material to be cleaned may be solvent-washed inthe absence of water with excellent results. However, better results are usually obtained by adding a small amount of water as such to the dry cleaning bath. Due to the presence of the sulfonated compounds the water becomes incorporated and dispersed in such an extremely finely divided'state in the dry cleaning composition .that water-sensitive materials can be dry cleaned in such water-containing compositions without danger of water spotting. The exact amount of water needed in any given case varies somewhat according to the type of, soil which is to be removed, and this generally varies with the particular material to be treated. For example, about 0.25% of water has been found to give good results in many cases, In general there must not be so much water present that it is in poorly dispersed form and so causes water-spotting of the material being dry cleaned. As is' well known, the amount of moisture which the material will tolerate without suffering water-damage (wrinkling, shrinking, etc.) depends upon the particular material and its state of dryness as well as upon the degree of dispersion of the moisture in the dry cleaning solvents. The amount of water which a dry cleaning solvent can hold in a very finely-dispersed or non-wetting state with respect to the materials to be cleaned depends altogether upon the dry cleaning assistant which is added to the solution, and it has been position of this invention is that they have little or no tendency to become rancid and thus to leave very objectionable odors in the dry cleaned garments. Difllculties with such rancid .odors have been commonly experienced with dry cleaningassistants of the prior art. Much of the difliculty caused by rancidity which is associated with many of the dry cleaning compositions of the prior art is probably due to the wide use in such compositions of 'oleic acid. This is not necessary for the dry cleaning compositions of the present invention.

Substantial economies in dry cleaning are shown by the use of the hereinbefore defined sulfonated esters in the dry cleaning compositions of this invention. This is due to the fact that much less of the said ester is necessary to produce an excellent cleaning efiect than has previously been used of the currently-knowmdry cleaning assistants. Thus, it has been found that, when the sulfonated esters represented by the above general formula are used, less than onethird of the usual amount of dry cleaning assistant need be added to the dry cleaning solvent to prepare adequate dry cleaning compositions. In addition, the use as dry cleaning assistants of the compounds represented by the foregoing general formula imparts an increased cleaning action to the compositions containing them, and obviates any harmful and undesirable effects on the color and finish of the cleaned material. Further, the aforesaid sulfonated compounds are for the most part not lime-sensitive and therefore they do not form insoluble calcium salts nor cause undesirable deposits of insoluble calcium salts to be formed in the dry cleaning baths as do many compounds heretofore used, when water introduced in such baths contains watersoluble calcium salts.

The dry cleaning compositions of this application may be made from many difierent types of dry cleaning solvents. Heretofore each type of dry cleaning assistant was usable and compatible only with one or a limited class of dry cleaning solvents, whereas the dry cleaning assistants which are used for preparing the dry cleaning compositions of the present invention may be used with excellent results in practically any dry cleaning solvent. The presence of said sulfonated esters as dry cleaning assistants in the dry cleaning compositions of this invention also has the very desirable effect of greatly decreasing the internal electrical resistance of inflammable solvents or solvent mixtures; thereby substantially decreasing the danger of fire from spark discharges or static electricity.

In many modern dry cleaning plants it is the practice to remove undissolved dirt from the dry cleaning solution by filtration. The presence of the hereinbefore defined sulfonated esters in the dry cleaning baths aids in decreasing the clogging effects of the dirt on the filter media and retardsthe development of back pressures in the filters. In this way the period during which the dry cleaning solution can be recirculated'before plugging the filter is substantially increased with resulting economy in operation.

The invention is illustrated by the following examples in which the parts are by'weight:

Example 1.-A cleaning bath was obtained by shaking 3.0 parts of the neutral sodium salt of glycoldioleate sulfate with 1115 parts of V. M. P. naphtha (a hydrocarbon mixture having a specific gravity of 0.746 and a boiling range of 215-320 F. and of which 90 per cent of the distillate distilled between 215 F. and 279 F.). -A piece of flannel soiled with tallow and carbon black was agitated mechanically in this dry cleaning composition for about half an hour. The flannel was withdrawn and. allowed to dry. The dry cleaned material was substantially free from soil and very bright, showing very good cleaning action by the composition.

Example 2.A cleaning'bath was obtained by mixing 3.0 parts of the neutral sodium salt of glycoldioleate sulfate, 1.5 parts of water, and 1115 parts of V. M. P. naphtha. A piece of soiled flannel was agitated mechanically in this dry, cleaning composition for about half an hour.

The flannelwas withdrawn and allowed to dry. The dry cleaned material was substantially free from soil and very bright, showing very good cleaning action. The ability to remove water- I soluble stains was a feature of the dry cleaning composition of this example.

In place of the sulfated glycol ester of oleic acid, the sulfated diethyleneglycol diester of oleic acid, or. other compounds set forth in United States Patent 2,136,379, issued November 15, 1938, may be used. a

An outstanding characteristic of the new dry cleaning compositions of this invention'is their ability to attain excellent cleaning action with very low concentration of addition compound, particularly when water is added to the bath in small amounts. Thus the weight ratio of the sulfonated ester salt to organic substantially water-immiscible dry cleaning solvent or solvent mixture need not be greater than 1.01100 and is preferably less than 0.3 :100. In fact, dry cleaning compositions containing as little as 1 to 3 parts of the dry cleaning assistants of the present invention per 1000 parts of solvent by weight have been found to give highly satisfactory cleaning.

An improved finish and/or feel of the dry cleaned materials can often be obtained by incorporating a small amount of a paraflin hydrocarbon or similar agent, such as paraflln wax or paraffin oil, into "the cleaning composition. Thus the presence of about 0.1% to 1% of parafiln-oil has been found eifective for this purpose.

The salts of sulfuric acid derivatives which are represented by the general formula above are effective as dry cleaning assistants in practically any volatile organic liquid of the dry cleaning ployed in accordance with the present invention I need not be prepared in any particular manner. The process of preparation of these compounds. set forth in United States Patent 2,136,379, issued November 15, 1938, is satisfactory.

The sulfonated compounds employed ,in accordance with this invention have been found to give excellent results in the cleaning of all kinds excellent properties of the dry cleaning composi-' tions of the present invention. I claim: 1. A dry cleaning composition comprising a volatile organic dry cleaning solvent and a salt of a sulfonated fatty acid diester of a glycol as a dry cleaning assistant.

2. A dry cleaning composition comprising an and a salt ofa sulfate of a fatty acid diester of a glycol, as a dry cleaning assistant .and as an emulsifying agent for the water, said salt being selected from the group consisting of ammonium, alkali metal, alkaline earth metal, and organic ammonium salts.

-5. A dry cleaning composition comprising a volatile organic dry cleaning solvent and a salt of a sulfonate of a fatty acid diester of a glycol as a dry cleaning assistant.

6. A dry cleaning composition comprising an emulsion of water in a volatile organic dry clean- -ing solvent, the water being in the ,intemal emulsion of waterin a volatile organic dry cleaning solvent, the water being in the internal phase, and a salt of a sulfonated fatty acid diester of a glycol, as a dry cleaning assistant and as an emulsifying agent for the water, said salt being selected from the group consisting of ammonium, alkali metal, alkaline earth metal, and organic ammonium salts.

phase, and a salt of a sulfonate of a fatty acid diester.of aglycol, as a dry cleaning assistant and as an emulsifying agent for the water, said salt being selected from the group consisting of ammonium, alkali metal, alkaline earth metal, and organic ammonium salts.

7. A dry cleaning composition comprising an emulsion of water in a volatile organic dry cleaning solvent, the water being in the internal phase, a salt of a sulfonated fatty acid diester of a glycol, and a small amount of a paramn hydrocarbon selected from the group consisting of a paraflin oil and paramn wax, said salt serving as a dry cleaning assistant and as an emulsifying agent for the water.

8. A dry cleaning composition comprising an emulsion of water in a volatile organic dry clean ing solvent, the water being in the internal phase, and a salt of a sulfate of a fatty acid diester of a glycol containing an alkyl group of at least 8 carbon atoms, as a dry cleaning assistant and as an emulsifying agent for the water,

said salt being selected from the group consisting and organic ammonium salts.

- 9. A dry cleaning composition comprising an emulsion of water in a volatile organic dry clean ing solvent, the water being in the internal phase, and a salt of a sulfate of a fatty acid diester of a glycol containing an alkyl group of from 12 to 18carbon atoms, as a dry cleaning assistant and as an emulsifying agent for the water, said salt being selected from the group consisting of ammonium, alkali metal, alkaline earth metal, and organic ammonium salts.

10. A dry cleaning composition comprising a volatile organic solvent of the dry cleaning type, a salt of a sulfonated fatty acid diester of a glycol, and a small amount of a parailln hydro-. carbon selected from the group consisting of paraffin oil and paraffln wax.

LAWRENCE H. FLE'I'I. 

